There was the lab in which we placed Alka Seltzer tablets in different millimeters of water and vinegar and we were asked to calculate the mass of carbon dioxide generated for each of the trials.
The teacher gave us a hint to add the mass of the beaker with water and the mass of the alka seltzer tablet and then subtract the mass of the beaker with water and alka seltzer in it. However, whenever I tried to calculate, I got a negative number and I don't think that's right. Please help!
Mass of Beaker with Water Mass of Alka Seltzer Tablet Mass of Water and Alka Seltzer
Trial 1 183.5 g 4.1 g 187 g
Trial 2 169.3 g 3.59 g 187.49 g
Trial 3 0.00 g 3.25 g 187.40 g
I dont believe your data is correct at all.
To calculate the mass of carbon dioxide generated for each trial, you need to use the law of conservation of mass. According to this law, the total mass of a closed system remains constant before and after a chemical reaction.
In this case, the reaction is the reaction between the Alka Seltzer tablets and water/vinegar, which produces carbon dioxide gas. The mass of the carbon dioxide can be calculated by determining the change in mass of the system (beaker with water and Alka Seltzer tablet).
To calculate the mass of carbon dioxide for each trial, you can use the following formula:
Mass of Carbon Dioxide = (Mass of Beaker with Water + Mass of Alka Seltzer Tablet) - (Mass of Beaker with Water and Alka Seltzer)
Let's calculate it for the three trials:
Trial 1:
Mass of Carbon Dioxide = (183.5 g + 4.1 g) - 187 g = 0.6 g
Trial 2:
Mass of Carbon Dioxide = (169.3 g + 3.59 g) - 187.49 g = -14.6 g
Trial 3:
Mass of Carbon Dioxide = (0.00 g + 3.25 g) - 187.40 g = -184.15 g
Based on the calculations, you're right to be concerned about the negative values obtained for Trial 2 and Trial 3. Negative values indicate an error in the measurements or calculation. It's possible that there was an error in either the measurements of the mass of the beaker, water, or Alka Seltzer tablet, or in the subtraction of the masses.
I recommend double-checking the measurements and calculations to identify the mistake. Make sure you properly weighed each component and correctly performed the subtraction.
If you're still unable to determine the source of the error, I suggest discussing it with your teacher or lab instructor for further guidance and clarification. They can help you in troubleshooting the issue and find a solution.